TW202225178A - Semiconductor photoresist composition and method of forming patterns using the composition - Google Patents

Abstract

Disclosed are a semiconductor photoresist composition including a condensed product produced by a condensation reaction between an organotin compound represented by Chemical Formula 1 and at least one organic acid compound selected from a substituted organic acid, an organic acid comprising at least two acid functional groups, and a substituted or unsubstituted sulfonic acid; and a solvent, and a method of forming patterns using the same. The semiconductor photoresist composition has excellent storage stability and sensitivity characteristics.

Description

Semiconductor photoresist composition and method for patterning using the same

The present disclosure relates to a semiconductor photoresist composition and a method of forming a pattern using the semiconductor photoresist composition. Cross-references to related applications

This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0178620 filed with the Korean Intellectual Property Office on December 18, 2020, the entire contents of which are incorporated herein by reference.

Extreme ultraviolet (EUV) lithography has received attention as a fundamental technique for the fabrication of next-generation semiconductor devices. EUV lithography is a patterning technique using EUV rays with a wavelength of 13.5 nm as an exposure light source. From EUV lithography, it is known that very fine patterns (eg, less than or equal to 20 nanometers) can be formed in an exposure process during the fabrication of semiconductor devices.

Extreme ultraviolet (EUV) lithography is achieved by development of compatible photoresist, which can be performed at a spatial resolution of less than or equal to 16 nm. Currently, efforts are underway to meet the insufficient specifications of traditional chemically amplified (CA) photoresists for next-generation devices, such as resolution, photospeed, and feature roughness (or also known as line edge roughness). or LER).

Inherent image blur due to acid-catalyzed reactions in these polymeric photoresists limits resolution in small feature sizes, which has long been known in electron beam (e-beam) lithography. Chemically amplified (CA) photoresists are designed for high sensitivity, but due to their typical elemental composition reducing the absorbance of the photoresist at a wavelength of 13.5 nm and thus reducing its sensitivity, chemically amplified (CA) photoresists may partially under EUV exposure land has more difficulties.

Additionally, CA photoresists may have difficulty with small feature sizes due to roughness issues, and experimentally, CA photoresists have increased line edge roughness (LER) because photospeed is reduced in part due to the nature of the acid catalyst process . Therefore, due to these defects and problems of CA photoresists, novel high performance photoresists are needed in the semiconductor industry.

In order to overcome the aforementioned disadvantages of chemically amplified (CA) organic photosensitive compositions, inorganic photosensitive compositions have been studied. Inorganic photosensitive compositions are mainly used for negative patterning, which has resistance to removal by developer compositions due to chemical modification by non-chemical amplification mechanisms. Inorganic compositions contain inorganic elements with higher EUV absorption rates than hydrocarbons, and thus can ensure sensitivity through non-chemical amplification mechanisms, and in addition, are less sensitive to random effects, and are therefore known to have low line edge roughness and a small amount of defect.

Inorganic photoresists based on peroxopolyacids of tungsten mixed with tungsten, niobium, titanium and/or tantalum have been reported as radiation-sensitive materials for patterning (US 5061599; H. Okamoto, T. Iwayanagi, K. Mochiji, H. Umezaki, T. Kudo, Applied Physics Letters, 49 5, 298-300, 1986).

These materials are efficiently patterned for large spacing in bilayer configurations, such as extreme ultraviolet (deep UV), X-ray, and electron beam sources. Recently, impressive cationic metal oxide hafnium sulfate (HfSOx) materials have been obtained with peroxy complexing agents for 15 nm half-pitch (HP) imaging by projected EUV exposure. Performance (US 2011-0045406; J. K. Stowers, A. Telecky, M. Kocsis, B. L. Clark, D. A. Case D. A. Keszler, A. Grenville, C. N. Anderson, P. P. Naulleau, Proc. SPIE, 7969, 796915, 2011 ). This system exhibits the highest performance of non-CA photoresist, and has an achievable photospeed close to the requirements of EUV photoresist. However, metal oxide hafnium sulfate materials with peroxy complexing agents have several practical disadvantages. First, these materials are coated in corrosive sulfuric acid/hydrogen peroxide mixtures and have insufficient shelf life stability. Second, as a composite mixture, it is not easy to modify the structure for performance improvement. Third, research and development should be carried out at very high concentrations such as 25 wt% in tetramethylammonium hydroxide (TMAH) solutions.

Recently, active research has been carried out as tin-containing molecules are known to have excellent extreme ultraviolet absorption. For organotin polymers therein, the alkyl ligands are dissociated by light absorption or secondary electrons generated thereby, and cross-linked to adjacent chains by oxo bonds, and thus achieve negative patterns that may not be removed by organic developers change.

However, this organotin-based photoresist has the disadvantage of being sensitive to moisture.

Embodiments provide a semiconductor photoresist composition having excellent sensitivity and storage stability.

Another embodiment provides a method of patterning using a semiconductor photoresist composition.

The semiconductor photoresist composition according to the embodiment is a condensation product produced by a condensation reaction between an organotin compound represented by Chemical Formula 1 and at least one organic acid compound selected from substituted organic acids, including at least two organic acid compounds. organic acids and substituted or unsubstituted sulfonic acids; and solvents.

在化學式1中， R ¹是取代或未取代的C1到C20烷基、取代或未取代的C3到C20環烷基、取代或未取代的C2到C20烯基、取代或未取代的C2到C20炔基、取代或未取代的C6到C30芳基，或-L-O-R ^d， R ^a、R ^b以及R ^c各自獨立地是取代或未取代的C1到C20烷基、取代或未取代的C3到C20環烷基、取代或未取代的C2到C20烯基、取代或未取代的C2到C20炔基、取代或未取代的C6到C30芳基或其組合， L是單鍵，或取代或未取代的C1到C20伸烷基，以及 R ^d是取代或未取代的C1到C20烷基。 [Chemical formula 1]

In Chemical Formula 1, R ¹ is substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 Alkynyl, substituted or unsubstituted C6 to C30 aryl, or -LOR ^d , R ^a , R ^b and R ^c are each independently substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 Cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl, substituted or unsubstituted C6 to C30 aryl, or a combination thereof, L is a single bond, or substituted or unsubstituted The C1 to C20 alkylene, and R ^d is a substituted or unsubstituted C1 to C20 alkyl.

The weight ratio of the organotin compound to the organic acid compound is about 85:15 to about 99:1.

The substituted organic acid may be substituted with at least one of a heteroatom, an atomic group containing a heteroatom, and combinations thereof, and the heteroatom may be sulfur (S), nitrogen (N), oxygen (O), phosphorus (P), and At least one of fluorine (F), and the atomic group containing a hetero atom may be at least one of -OH, -SH, -NH _{2 ,} -S-, and -SS-.

The organic acid compound can be glycolic acid, malonic acid, succinic acid, 1,2,3,4-butanetetracarboxylic acid, citric acid, tartaric acid, glyceric acid, lactic acid, thioglycolic acid, dithiodithiodicarbonate At least one of acetic acid, thiodiacetic acid, phthalic acid, maleic acid, L-aspartic acid, p-toluenesulfonic acid, methanesulfonic acid, and benzenesulfonic acid.

The organic acid compound may have a pKa of less than or equal to about 5.

The condensation product can be at least one of oligomers, polymers, and combinations thereof.

The condensation product may comprise a hydrolysis condensation product.

The semiconductor photoresist composition may further comprise a surfactant, a cross-linking agent, a leveling agent or a combination thereof.

A method of forming a pattern according to an embodiment includes: forming an etch target layer on a substrate; coating a semiconductor photoresist composition on the etch target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and using light The resist pattern acts as an etch mask to etch the etch target layer.

The photoresist pattern may be formed using light having a wavelength of about 5 nm to about 150 nm.

The method of forming a pattern may further include providing a resist underlayer formed between the substrate and the photoresist layer.

The photoresist pattern may have a width of about 5 nm to about 100 nm.

The semiconductor photoresist composition according to the embodiment has excellent storage stability and sensitivity characteristics, and by using the semiconductor photoresist composition, it is possible to provide a photoresist having excellent sensitivity and high aspect ratio without pattern collapse pattern.

Hereinafter, embodiments of the present invention are described in detail with reference to the drawings. In the following description of the invention, well-known functions or constructions are not described in order to clarify the invention.

In order to clearly illustrate the present disclosure, descriptions and relationships are omitted, and the same or similar configuration elements are designated by the same reference numerals throughout the present disclosure. Furthermore, since the size and thickness of each configuration shown in the drawings are arbitrarily drawn for better understanding and ease of description, the present invention is not necessarily limited thereto.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thicknesses of portions of layers or regions, etc., are exaggerated for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present.

As used herein, "substituted" refers to the replacement of a hydrogen atom by deuterium, halogen, hydroxy, amino, substituted or unsubstituted C1 to C30 amine, nitro, substituted or unsubstituted C1 to C40 silyl (eg C1 to C10 alkylsilyl), C1 to C30 alkyl, C1 to C10 haloalkyl, C3 to C30 cycloalkyl, C6 to C30 aryl, C1 to C20 alkoxy or cyano. "Unsubstituted" means that a hydrogen atom is not replaced by another substituent and retains a hydrogen atom.

As used herein, when no definition is otherwise provided, "alkyl" refers to a straight or branched chain aliphatic hydrocarbon group. The alkyl group may be a "saturated alkyl group" without any double or triple bonds.

The alkyl group can be a C1 to C20 alkyl group. More specifically, the alkyl group may be a C1 to C10 alkyl group or a C1 to C6 alkyl group. For example, C1 to C4 alkyl means that the alkyl chain contains 1 to 4 carbon atoms, and may be selected from the group consisting of: methyl, ethyl, propyl, isopropyl, n-butyl, isopropyl Butyl, sec-butyl and tert-butyl.

Specific examples of alkyl groups can include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl Wait.

As used herein, when no definition is otherwise provided, "cycloalkyl" refers to a monovalent cyclic aliphatic hydrocarbon group.

As used herein, when no definition is otherwise provided, "alkenyl" refers to an aliphatic unsaturated alkenyl group containing at least one double bond as a straight or branched chain aliphatic hydrocarbon group.

As used herein, when no definition is otherwise provided, "alkynyl" refers to an aliphatic unsaturated alkynyl group containing at least one triple bond as a straight or branched chain aliphatic hydrocarbon group.

As used herein, "aryl" refers to a group in which all atoms in a cyclic substituent have p-orbitals and these p-orbitals are conjugated and may contain monocyclic or fused polycyclic functional groups (ie, a common phase A substituent of a functional group of the adjacent carbon atom pair.

Hereinafter, the semiconductor photoresist composition according to the embodiment is described.

A semiconductor photoresist composition according to an embodiment of the present invention includes a condensation product and a solvent, wherein the condensation product is composed of an organic tin compound represented by Chemical Formula 1 and a substituted organic acid, an organic acid comprising at least two acid functional groups, and a substituted or unsubstituted organic acid. Formed by the condensation reaction of at least one organic acid compound selected from the substituted sulfonic acids.

在化學式1中， R ¹是取代或未取代的C1到C20烷基、取代或未取代的C3到C20環烷基、取代或未取代的C2到C20烯基、取代或未取代的C2到C20炔基、取代或未取代的C6到C30芳基，或-L-O-R ^d， R ^a、R ^b以及R ^c各自獨立地是取代或未取代的C1到C20烷基、取代或未取代的C3到C20環烷基、取代或未取代的C2到C20烯基、取代或未取代的C2到C20炔基、取代或未取代的C6到C30芳基或其組合， L是單鍵，或取代或未取代的C1到C20伸烷基，以及 R ^d是取代或未取代的C1到C20烷基。 [Chemical formula 1]

In Chemical Formula 1, R ¹ is substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 Alkynyl, substituted or unsubstituted C6 to C30 aryl, or -LOR ^d , R ^a , R ^b and R ^c are each independently substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 Cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl, substituted or unsubstituted C6 to C30 aryl, or a combination thereof, L is a single bond, or substituted or unsubstituted The C1 to C20 alkylene, and R ^d is a substituted or unsubstituted C1 to C20 alkyl.

As used herein, the term "condensation product" refers to a product resulting from a condensation reaction. A condensation reaction refers to a reaction in which at least two organic compound molecules combine with a reactive (eg, reactive) atom or group of atoms as the center to release a single molecule such as water, ammonia, hydrogen chloride, and/or the like. Herein, compounds resulting from simply combining two molecules (without releasing any single molecule) are also intended to be included in the category of condensation products.

The condensation product may comprise monomers, oligomers, polymers, and combinations thereof.

For example, R ¹ of Chemical Formula 1 may be a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, or a combination thereof.

As a specific example, R ¹ of Chemical Formula 1 may be a substituted or unsubstituted C3 to C20 alkyl group.

For example, R ¹ of Chemical Formula 1 may be isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, or a combination thereof.

For example, R ^a , R ^b and R ^c of Chemical Formula 1 may each independently be substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl or a combination thereof.

For example, ^Ra , ^Rb , and ^Rc can each independently be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, vinyl or its combination.

Each of ^Ra , ^Rb , and ^Rc may be the same or different.

For example, a substituted organic acid can be substituted with at least one of heteroatoms, groups of atoms containing heteroatoms, and combinations thereof,

The heteroatom may be at least one of sulfur (S), nitrogen (N), oxygen (O), phosphorus (P), and fluorine (F), and

The heteroatom-containing atomic group may be at least one of -OH, -SH, _{-NH2 ,} -S-, and -SS-.

In this specification, a substituted organic acid may, for example, mean that at least one of a carbon atom and a hydrogen atom contained in a hydrocarbon chain to which an acid functional group is attached is composed of at least one of a heteroatom, a heteroatom-containing atomic group, and a combination thereof Substitution also contains an acid functional group.

For example, the substituted organic acid can include at least one of carbon atoms and hydrogen atoms at the end of the hydrocarbon chain to which the acid functional group is attached, at least one of carbon atoms and hydrogen atoms in the middle of the hydrocarbon chain, and combinations thereof can be heteroatoms , at least one substitution of heteroatom-containing atomic groups and combinations thereof. For example, substituted organic acids may include at least one carbon atom and/or hydrogen atom in the backbone and/or at the end of the hydrocarbon chain to which the acid functional group is attached, substituted organic acids consisting of heteroatom, heteroatom-containing Atomic groups or combinations thereof are substituted.

Examples of substituted organic acids include glycolic acid, lactic acid, thioglycolic acid, and L-aspartic acid.

In this specification, the acid functional group may be, for example, a carboxyl group.

The organic acid containing at least two acid functional groups may be, for example, an organic acid containing 2 to 4 acid functional groups and examples of the organic acid may include malonic acid, succinic acid, 1,2,3,4-butanetetracarboxylic acid acid, citric acid, tartaric acid, glyceric acid, dithiodiacetic acid, thiodiacetic acid, phthalic acid and maleic acid.

Meanwhile, in the present specification, substituted or unsubstituted sulfonic acid means an organic acid containing at least one -S(O) ₂ OH group.

Examples of substituted or unsubstituted sulfonic acids may include p-toluenesulfonic acid, methanesulfonic acid, and benzenesulfonic acid.

Meanwhile, the organic acid compound may have a pKa of less than or equal to about 5, for example, less than or equal to about 4.

pKa is the value obtained by taking the negative logarithm (-log) of the acid dissociation constant when an acid (HA) dissociates into H ⁺ and A- in aqueous solution, and the larger the pKa value, the weaker the acid. When two or more acid-dissociable functional groups are present in one organic acid molecule, the pKa value of the molecule is determined as that of the functional group with the lowest pKa.

When the pKa value of the organic acid compound is within the above range, a condensation product having an organic tin compound is easily formed. Since the condensation products are formed from oligomers or higher polymers, the penetration of external moisture can be reduced.

Therefore, the storage stability of the semiconductor photoresist composition including the condensation product formed by the condensation reaction of the organic tin compound represented by Chemical Formula 1 and the organic acid compound can be improved.

In the condensation product formed by the condensation reaction of the organotin compound represented by Chemical Formula 1 and the organic acid compound, the group derived from the organic acid compound serves as a ligand and links the organotin compound, and thus the condensation product as the final product may be an oligo at least one of polymers, polymers, and combinations thereof.

For example, the condensation product may comprise a hydrolysis condensation product.

The condensation product may contain an organotin compound and an organic acid compound in a weight ratio of about 85:15 to about 99:1, and when it is within the above range, the film-forming properties, solubility, refractive index, and dissolution rate in a developer may be more favorable.

For example, the condensation product may include the organotin compound and the organic acid compound in a weight ratio of about 90:10 to about 99:1, and specifically, about 90:10 to about 97:3.

Additionally, the condensation product may have a weight average molecular weight (Mw) of from about 1,000 g/mol to about 30,000 g/mol, eg, from about 1,000 g/mol to about 20,000 g/mol, and in another implementation In an example, from about 1,000 g/mol to about 10,000 g/mol. When it is within the above range, it may be more favorable in terms of film-forming properties, solubility, refractive index, and dissolution rate in the developer.

The conditions for obtaining the condensation product are not particularly limited.

For example, the organotin compound represented by Chemical Formula 1 and the organic acid are diluted in a solvent such as propylene glycol monomethyl ether acetate (PGMEA), ethanol, 2-propanol, acetone, and butyl acetate compound. If necessary, the desired condensation product can be obtained by adding water and an acid (hydrochloric acid, acetic acid, nitric acid, etc.) as a reaction catalyst, followed by stirring to complete the polymerization reaction.

The type or amount of solvent, acid or potassium catalyst used herein can be arbitrarily selected without limitation. The required reaction time varies depending on the type, concentration, reaction temperature, etc. of the reactants, but usually takes about 15 minutes to about 30 days. However, the reaction time is not limited to this range.

With commonly used photoresist compositions, etch resistance may be insufficient and patterns may collapse at high aspect ratios.

On the other hand, it is desirable that the semiconductor photoresist composition according to the embodiment consists of the aforementioned condensation product and a solvent.

The solvent included in the semiconductor photoresist composition according to the embodiment may be an organic solvent such as aromatic compounds (eg, xylene, toluene), alcohols (eg, 4-methyl-2-pentenol, 4-methyl) - 2-propanol, 1-butanol, methanol, isopropanol, 1-propanol propylene glycol monomethyl ether), ethers (eg, anisole, tetrahydrofuran), esters (n-butyl acetate, propylene glycol monomethyl ether ethyl) acid ester, ethyl acetate, ethyl lactate), ketones (eg, methyl ethyl ketone, 2-heptanone), mixtures thereof, etc., but not limited thereto.

In some cases, the semiconductor photoresist composition according to the embodiment may further include an additive. Examples of additives include surfactants, cross-linking agents, leveling agents, or combinations thereof.

The surfactant may be, for example, but not limited to, alkyl benzene sulfonates, alkyl pyridinium salts, polyethylene glycols, quaternary ammonium salts, or combinations thereof.

The cross-linking agent may be, for example, a melamine-based cross-linking agent, a substituted urea-based cross-linking agent, an acryl-based cross-linking agent, an epoxy-based cross-linking agent, or a polymer-based cross-linking agent, but is not limited thereto. It may be a crosslinking agent having at least two crosslinking-forming substituents, for example, compounds such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated glycoluril, methylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, 4-hydroxybutyl acrylate, acrylic acid, urethane acrylate, acrylate methacrylate , 1,4-butanediol diglycidyl ether, glycidol, diglycidyl 1,2-cyclohexanedicarboxylate, trimethylpropane triglycidyl ether, 1,3-bis(glycidyloxy propyl) tetramethyldisiloxane, methoxymethylated urea, butoxymethylated urea or methoxymethylated thiourea, etc.

Leveling agents can be used to improve coating flatness during printing and can be commercially known leveling agents.

The amount of additives used can be controlled depending on the desired properties.

In addition, the semiconductor photoresist composition may further comprise a silane coupling agent as an adhesion enhancer in order to improve the close contact force with the substrate (eg, in order to improve the adhesion of the semiconductor photoresist composition to the substrate). The silane coupling agent may be, for example, a silane compound containing carbon-carbon unsaturated bonds, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxysilane) or 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloyloxy propylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane; trimethoxy[3-(phenylamino)propyl]silane, etc., but not limited thereto.

The semiconductor photoresist composition can be formed into a pattern having a high aspect ratio without collapse. Therefore, in order to form a structure having, for example, about 5 nm to about 100 nm, about 5 nm to about 80 nm, about 5 nm to about 70 nm, about 5 nm to about 50 nm, about 5 nm To fine patterns of widths of about 40 nm, about 5 nm to about 30 nm, or about 5 nm to about 20 nm, the semiconductor photoresist composition can be used to use about 5 nm to about 150 nm (eg, about 5 nm to about 150 nm). , about 5 nm to about 100 nm, about 5 nm to about 80 nm, about 5 nm to about 50 nm, about 5 nm to about 30 nm, or about 5 nm to about 20 nm ) for the photoresist process of light with wavelengths in the range. Therefore, semiconductor photoresist compositions according to embodiments can be used to implement extreme ultraviolet lithography using an EUV light source with a wavelength of about 13.5 nm.

According to another embodiment, a method of forming a pattern using the aforementioned semiconductor photoresist composition is provided. For example, the fabricated pattern may be a photoresist pattern. More specifically, it may be a negative photoresist pattern.

A method of forming a pattern according to an embodiment includes: forming an etch target layer on a substrate; coating a semiconductor photoresist composition on the etch target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and using light The resist pattern acts as an etch mask to etch the etch target layer.

Hereinafter, a method of forming a pattern using the semiconductor photoresist composition will be described with reference to FIGS. 1 to 5 . 1 to 5 are cross-sectional views for explaining a method of forming a pattern using a semiconductor photoresist composition according to an embodiment.

Referring to Figure 1, an object is prepared for etching. The object for etching may be the thin film 102 formed on the semiconductor substrate 100 . Hereinafter, the object for etching is limited to the thin film 102 . The entire surface of the film 102 is washed to remove impurities and the like remaining thereon. The thin film 102 may be, for example, a silicon nitride layer, a polysilicon layer, or a silicon oxide layer.

Subsequently, the resist underlayer composition for forming the resist underlayer 104 is spin-coated on the surface of the washed thin film 102 . However, the embodiment is not limited thereto, and various known coating methods such as spray coating, dip coating, knife edge coating, printing methods (eg, ink jet printing and screen printing) and the like may be used.

The coating process of the resist underlayer may be omitted, and hereinafter, the process including the coating of the resist underlayer is described.

Subsequently, the coated composition is dried and baked to form a resist underlayer 104 on the thin film 102 . Baking may be performed at about 100°C to about 500°C, eg, about 100°C to about 300°C.

The resist underlayer 104 is formed between the substrate 100 and the photoresist layer 106, and thus when reflected from the interface between the substrate 100 and the photoresist layer 106 or the hard mask between layers scatters to unintended light In the resist region, the non-uniformity of the photoresist line width and the patterning ability can be prevented.

Referring to FIG. 2 , a photoresist layer 106 is formed by coating a semiconductor photoresist composition on the resist underlayer 104 . The photoresist layer 106 is obtained by coating the aforementioned semiconductor photoresist composition on the thin film 102 formed on the substrate 100, and then curing it by heat treatment.

More specifically, patterning by using the semiconductor photoresist composition may include coating the semiconductor photoresist composition on the substrate 100 with the thin film 102 by spin coating, slot coating, ink jet printing, etc., and then drying the semiconductor photoresist composition to form the photoresist layer 106 .

The semiconductor photoresist composition has been described in detail and will not be described again.

Subsequently, the substrate 100 with the photoresist layer 106 is subjected to a first baking process. The first baking process may be performed at about 80°C to about 120°C.

Referring to FIG. 3, the photoresist layer 106 may be selectively exposed.

For example, exposure may use high energy wavelengths such as extreme ultraviolet (EUV; wavelength of 13.5 nm), E-beam (electron beam), as well as i-line (wavelength of 365 nm), KrF excimer laser (248 nm) Activating radiation of short wavelengths such as wavelengths of meters), ArF excimer lasers (wavelengths of 193 nm).

More specifically, light used for exposure according to embodiments may have short wavelengths and high energy wavelengths in the range of about 5 nanometers to about 150 nanometers, such as extreme ultraviolet (EUV; a wavelength of about 13.5 nanometers) , E beam (electron beam), etc.

When forming a photoresist pattern, a negative pattern may be formed.

The exposed regions 106a of the photoresist layer 106 have different solubility than the non-exposed regions 106b of the photoresist layer 106 by forming polymers by cross-linking reactions such as condensation between organometallic compounds.

Subsequently, the substrate 100 is subjected to a second baking process. The second baking process may be performed at a temperature of about 90°C to about 200°C. The exposed area 106a of the photoresist layer 106 is easily insoluble in the developing solution due to the second baking process. That is, after the second baking process, the exposed area 106a of the photoresist layer 106 becomes insoluble in the developing solution.

In FIG. 4 , a developing solution is used to dissolve and remove the non-exposed regions 106b of the photoresist layer to form a photoresist pattern 108 . Specifically, the non-exposed regions 106b of the photoresist layer are dissolved and removed by using an organic solvent such as propylene glycol monomethyl ether acetate (PGMEA) to complete the photoresist pattern 108 corresponding to the negative image.

As described above, the developer used in the method of forming a pattern according to the embodiment may be an organic solvent. The organic solvent used in the method of forming a pattern according to the embodiment may be, for example: a ketone such as methyl ethyl ketone, acetone, cyclohexanone, 2-heptanone, etc.; an alcohol such as 4-methyl-2-propanone Alcohol, 1-butanol, isopropanol, 1-propanol, methanol, etc.; esters, such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone, etc.; aromatics Compounds such as benzene, xylene, toluene, etc., or combinations thereof.

As described above, exposure to light having high energies such as extreme ultraviolet (EUV; having a wavelength of about 13.5 nm), E-beam (electron beam) and/or the like, and light having a wavelength such as i-line (about 365 nm) wavelengths), KrF excimer lasers (wavelengths of about 248 nm), ArF excimer lasers (wavelengths of about 193 nm), and/or the like may provide light having wavelengths ranging from about 5 nm to about 100 nm The photoresist pattern 108 has a width of meters. For example, the photoresist pattern 108 may have about 5 nm to about 90 nm, about 5 nm to about 80 nm, about 5 nm to about 70 nm, about 5 nm to about 60 nm, A width of about 5 nm to about 50 nm, about 5 nm to about 40 nm, about 5 nm to about 30 nm, or about 5 nm to about 20 nm.

On the other hand, the photoresist pattern 108 may have a thickness of less than or equal to about 50 nm (eg, less than or equal to about 40 nm; eg, less than or equal to about 30 nm; eg, less than or equal to about 20 nm; eg, less than or equal to about 15 nanometers) half-pitch and having a line width roughness of less than or equal to about 10 nanometers, less than or equal to about 5 nanometers, less than or equal to about 3 nanometers, or less than or equal to about 2 nanometers spacing.

Subsequently, the resist bottom layer 104 is etched using the photoresist pattern 108 as an etch mask. Through this etching process, the organic layer pattern 112 is formed. The organic layer pattern 112 may also have a width corresponding to the width of the photoresist pattern 108 .

Referring to FIG. 5, the exposed thin film 102 is etched by applying a photoresist pattern 108 as an etch mask. Thus, the thin film is formed as the thin film pattern 114 .

The etching of the thin film 102 may be, for example, dry etching using an etching gas, and the etching gas may be, for example, CHF ₃ , CF ₄ , Cl ₂ , BCl ₃ , and a mixed gas thereof.

In the exposure process, the thin film pattern 114 formed by using the photoresist pattern 108 formed by the exposure process using the EUV light source may have a width corresponding to the width of the photoresist pattern 108 . For example, the thin film pattern 114 may have a width of 5 nm to 100 nm, which is equal to the width of the photoresist pattern 108 . For example, the thin film pattern 114 formed by using the photoresist pattern 108 (which is formed by an exposure process using an EUV light source) may have about 5 nm to about 90 nm, about 5 nm to about 80 nm, about 5 nm to about 70 nm, about 5 nm to about 60 nm, about 5 nm to about 50 nm, about 5 nm to about 40 nm, about 5 nm to about 30 nm, or The width is about 5 nm to about 20 nm, and more specifically, has a width less than or equal to 20 nm, like the width of the photoresist pattern 108 .

Hereinafter, the present invention will be described in more detail by way of examples of the aforementioned preparation of the semiconductor photoresist composition. However, the present invention is not technically limited by the following examples. EXAMPLES Synthesis Example 1 : Synthesis of Organotin Compound 1

25 mL of acetic acid was slowly added to the compound represented by Chemical Formula A-1 (10 g, 25.6 mmol) in a dropwise manner at room temperature, and then heated at 110° C. under reflux for 24 hours.

Subsequently, after the temperature was lowered to room temperature, acetic acid was vacuum-distilled to obtain Organotin Compound 1 represented by Chemical Formula B-1 (yield: 90%).

[化學式B-1]

合成實例 2 ：合成有機錫化合物 2 [Chemical formula A-1]

[Chemical formula B-1]

Synthesis Example 2 : Synthesis of Organotin Compound 2

25 ml of acrylic acid was slowly added to the compound represented by Chemical Formula A-2 (10 g, 25.4 mmol) in a dropwise manner at room temperature, and then heated at 110° C. under reflux for 24 hours .

[化學式B-2]

合成實例 3 ：合成有機錫化合物 3 Subsequently, after the temperature was lowered to room temperature, the acrylic acid was vacuum-distilled to obtain the organotin compound 2 represented by Chemical Formula B-2 (yield: 50%). [Chemical formula A-2]

[Chemical formula B-2]

Synthesis Example 3 : Synthesis of Organotin Compound 3

25 mL of propionic acid was slowly added to the compound represented by Chemical Formula A-3 (10 g, 23.7 mmol) in a dropwise manner at room temperature, and then heated at 110° C. under reflux for 24 hours.

[化學式B-3]

合成實例 4 ：合成有機錫化合物 4 Subsequently, after the temperature was lowered to room temperature, the propionic acid was vacuum-distilled to obtain the organotin compound 3 represented by Chemical Formula B-3 (yield: 95%). [Chemical formula A-3]

[Chemical formula B-3]

Synthesis Example 4 : Synthesis of Organotin Compound 4

25 mL of isobutyric acid was slowly added to the compound represented by Chemical Formula A-2 of Synthesis Example 2 (10 g, 25.4 mmol) in a dropwise manner at room temperature, and then heated at 110 °C under reflux 24 hours.

合成實例 5 ：合成有機錫化合物 5 Subsequently, after the temperature was lowered to room temperature, the isobutyric acid was vacuum-distilled to obtain the organotin compound 4 represented by Chemical Formula B-4 (yield: 95%). [Chemical formula B-4]

Synthesis Example 5 : Synthesis of Organotin Compound 5

25 mL of propionic acid was slowly added to the compound represented by Chemical Formula A-4 (10 g, 24.6 mmol) in a dropwise manner at room temperature, and then heated at 110° C. under reflux for 24 hours.

[化學式B-5]

實例 1 到實例 7 Subsequently, after the temperature was lowered to room temperature, the propionic acid was vacuum-distilled to obtain the organotin compound 5 represented by Chemical Formula B-5 (yield: 90%). [Chemical formula A-4]

[Chemical formula B-5]

Example 1 to Example 7

Each of the organotin compounds according to Synthesis Example 1 to Synthesis Example 5 was mixed with an organic acid compound as shown in Table 1, and then added to propylene glycol methyl ether acetate (PGMEA, containing 5% by weight of deionized water (Deionized water). water, DIW)) to prepare a solution containing solids at a concentration of 20% by weight.

The solutions were stirred at 80°C for 24 hours and cooled to room temperature, respectively, and then, the condensate-containing solutions according to Examples 1 to 7 were prepared by diluting the solution to 3 wt% solids with additional PGMEA solution, And then, the prepared solutions were separately filtered with a 0.1-micron polytetrafluoroethylene (polytetrafluoroethylene; PTFE) syringe screening program, thereby preparing a photoresist composition.

(Table 1) Organotin compound (A) Organic acid compound (B) Content ratio (A:B) (wt%) Example 1 Chemical formula B-1 Glycolic acid 97:3 Example 2 Chemical formula B-2 Glycolic acid 97:3 Example 3 Chemical formula B-3 Malonate 97:3 Example 4 Chemical formula B-4 Glycolic acid 97:3 Example 5 Chemical formula B-4 Succinic acid 97:3 Example 6 Chemical formula B-5 1,2,3,4-Butanetetracarboxylic acid 97:3 Example 7 Chemical formula B-5 Succinic acid 97:3 Comparative Example 1 to Comparative Example 5

The photoresist compositions were prepared by dissolving the organotin compounds according to Synthesis Example 1 to Synthesis Example 5 in PGMEA at a solid concentration of 3 wt %, respectively, and then filtering with a 0.1-micron polytetrafluoroethylene (PTFE) syringe screen procedure. thing. Evaluation 1 : Evaluation of Sensitivity and Line Edge Roughness ( LER )

The photoresist compositions of Examples 1 to 7 and Comparative Examples 1 to 5 were spin-coated on circular silicon wafers, respectively, to form films at 1500 rpm for 30 seconds. Each film was exposed to extreme ultraviolet radiation (E-beam) at an accelerating voltage of 100 kV to pattern half-pitch nanowires from 40 nm. The exposed membranes were exposed to 170°C for 60 seconds and dipped in a Petri dish containing 2-heptanone for 30 seconds and then washed with the same solvent for 10 seconds. Finally, the washed membranes were baked at 150 °C for 180 seconds, and pattern images were obtained by field emission scanning electron microscopy (FE-SEM). The formed pattern lines confirmed by FE-SEM imaging were measured in terms of critical dimension (CD) dimensions and line edge roughness (LER), and then the sensitivity and line edge roughness of the films were evaluated according to the following criteria, and are then shown in Table 2. ※ Evaluation Criteria (1) Sensitivity The CD size measured at an energy of 1000 microcoulombs/cm 2 was evaluated according to the following criteria, and the results are shown in Table 2. - ◎: 40 nm or more - ○: 35 nm or more and less than 40 nm - △: less than 35 nm - X: No pattern confirmed. (2) Line edge roughness (LER) - ○: less than or equal to 4 nm - △: more than 4 nm and less than or equal to 7 nm - X: more than 7 nm Evaluation 2 : Evaluation of storage stability

On the other hand, the photoresist compositions according to Examples 1 to 7 and Comparative Examples 1 to 5 were evaluated regarding storage stability, and the results are shown in Table 2.

[Storage stability]

The photoresist compositions according to Examples 1 to 7 and Comparative Examples 1 to 5 were allowed to stand at room temperature (20±5° C.) for a predetermined period of time, and were then visually inspected for the degree of precipitation and according to the following preservation guidelines The assessment is in 2 grades. ※ Evaluation Criteria - ○: Can be stored for greater than or equal to 6 months - △: Can be stored for less than 6 months and greater than or equal to 3 months - X: Can be stored for less than 3 months

(Table 2) Sensitivity LER (nano) Storage stability Example 1 ◎ ○ ○ Example 2 ◎ ○ ○ Example 3 ◎ ○ ○ Example 4 ◎ ○ ○ Example 5 ◎ ○ ○ Example 6 ◎ ○ ○ Example 7 ◎ ○ ○ Comparative Example 1 ○ △ X Comparative Example 2 ◎ X X Comparative Example 3 ○ △ X Comparative Example 4 ○ △ △ Comparative Example 5 ○ △ X

Referring to Table 2, the semiconductor photoresist compositions according to Examples 1 to 7 exhibited more excellent storage stability than the semiconductor photoresist compositions according to Comparative Examples 1 to 5, and in addition, the semiconductor photoresist compositions according to Examples 1 to 7 exhibited superior storage stability. The patterns formed from the semiconductor photoresist compositions exhibited more excellent sensitivity and line edge roughness (LER) than the patterns formed from the semiconductor photoresist compositions according to Comparative Examples 1 to 5.

In the foregoing, certain embodiments of the present invention have been described and illustrated, however, it will be apparent to those of ordinary skill in the art that the present invention is not limited to the embodiments as described and may be implemented without departing from the spirit and scope of the present invention Various modifications and conversions are made without Therefore, the modified or transformed embodiments thus may not be understood from the technical idea and aspects of the present invention alone, and the modified embodiments are within the scope of the patent application of the present invention.

100: base 102: Film 104: resist bottom layer 106: photoresist layer 106a: Exposure area 106b: Non-exposed area 108: Photoresist Pattern 112: Organic Layer Pattern 114: Film Pattern

1 to 5 are cross-sectional views for explaining a method of forming a pattern using a semiconductor photoresist composition according to an embodiment.

100: base

108: Photoresist Pattern

112: Organic Layer Pattern

114: Film Pattern

Claims (12)

A semiconductor photoresist composition, comprising: a condensation product produced by a condensation reaction between an organotin compound represented by chemical formula 1 and at least one organic acid compound, at least one of the organic acid compounds is selected from substituted organic acids, including at least two organic acids and substituted or unsubstituted sulfonic acids; and solvents: [Chemical formula 1]

wherein, in Chemical Formula 1, R ¹ is substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl, substituted or unsubstituted C6 to C30 aryl, or -LOR ^d , R ^a , R ^b and R ^c are each independently substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl, substituted or unsubstituted C6 to C30 aryl, or combinations thereof, L is a single bond, or substituted or unsubstituted C1 to C20 alkylene, and R ^d is substituted or unsubstituted C1 to C20 alkyl. The semiconductor photoresist composition according to claim 1, wherein the weight ratio of the organic tin compound and the organic acid compound is 85:15 to 99:1. The semiconductor photoresist composition of claim 1, wherein the substituted organic acid is substituted with at least one of a heteroatom, an atomic group containing a heteroatom, and a combination thereof, and the heteroatom is sulfur, nitrogen, At least one of oxygen, phosphorus, and fluorine, and the atomic group containing the heteroatom is at least one of -OH, -SH, _-NH2 , -S-, and -SS-. The semiconductor photoresist composition according to claim 1, wherein the organic acid compound comprises glycolic acid, malonic acid, succinic acid, 1,2,3,4-butanetetracarboxylic acid, citric acid, tartaric acid, Malic acid, lactic acid, thioglycolic acid, dithiodiacetic acid, thiodiacetic acid, phthalic acid, maleic acid, L-aspartic acid, p-toluenesulfonic acid, methanesulfonic acid, and benzene at least one of the sulfonic acids. The semiconductor photoresist composition of claim 1, wherein the organic acid compound has a pKa of 5 or less. The semiconductor photoresist composition of claim 1, wherein the condensation product is at least one of an oligomer, a polymer, and a combination thereof. The semiconductor photoresist composition according to claim 1, wherein the condensation product is a hydrolysis condensation product. The semiconductor photoresist composition according to claim 1, wherein the semiconductor photoresist composition further comprises a surfactant, a crosslinking agent, a leveling agent or a combination thereof. A method of forming a pattern comprising: forming an etch target layer on the substrate; Coating the semiconductor photoresist composition according to any one of claim 1 to claim 8 on the etching target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and The etch target layer is etched using the photoresist pattern as an etch mask. The method of forming a pattern of claim 9, wherein the photoresist pattern is formed using light having a wavelength of 5 nm to 150 nm. The method of forming a pattern of claim 9, wherein the method of forming the pattern further comprises providing a resist underlayer formed between the substrate and the photoresist layer. The method of forming a pattern of claim 9, wherein the photoresist pattern has a width of 5 nm to 100 nm.

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